Air pollutants

Particulate matter

Particulate matter (PM10) consists of tiny floating particles with a diameter of up to 10 micrometres (µm). The dust particles do not all have the same chemical composition. High concentrations of particulate matter are harmful to the health of people living and working in cities.

Particulate matter consists of minute particles that enter the organism as we breathe. This can cause coronary and circulatory problems, respiratory diseases and even lung cancer.

Sources of Particulate matter emissions

Of the particulate matter measured on the Friedberger Landstrasse, 26 per cent comes from the exhaust fumes emitted by diesel-powered vehicles. Diesel exhaust emissions frequently contain very fine particles that are ­especially harmful to human health. Some 23 per cent of them are caused by abrasion and resuspension processes. Industrial activity, biogenic sources and building heating also make a substantial contribution to particulate matter pollution. Air traffic is only a minor emitter of PM10.

Sources of particulate matter emissions – Friedberger Landstrasse
(Click on the diagram for an enlarged view)

The level of particulate matter pollution depends very much on the weather. For example, periods of low atmospheric pressure with fairly high air exchange rates and rain, which flushes the particles out, reduce the particle concentration in the atmosphere. When air exchange rates are low (inverse wea­ther conditions), which occurs frequently during the winter periods of high atmospheric pressure, particle concentration increases.

Limits and measurements

EU fine particle limits have applied since January 2005. There are two upper limits: the annual average and the number of days on which the limit is exceeded.

In Frankfurt, there has been an overall decline in fine particle concentrations and the city has now complied with the annual average limit of 40 µg/m³ for a number of years.

Development of annual average values
(Click on the chart to open an enlarged presentation)

The second EU limit value is the number of days on which the limit is exceeded. The figure of 50 µg/m³ for fine particles may be exceeded on no more than 35 days a year.

This limit value was exceeded on Friedberger Landstrasse in Frankfurt in 2005, 2006, 2009 and 2011. In 2007, 2008, 2010, 2012 and 2013 the limit value was met at all air measuring stations in Frankfurt. In 2011 the limit was exceeded on Friedberger Landstrasse on 42 days. In 2012 the fine particle limit of 50 µg/m³ was exceeded on only 19 days and in 2013 on 21 days.

Development of the number days on which the limit was exceeded
(Click on the chart to open an enlarged presentation)

Fine particles (PM2.5)

PM2.5 particles are suspended particles with a diameter of no more than 2.5 micrometres (µm). These tiny particles have considerable negative effects on human health.

That is why the EU set new emission values. Since 1 January 2010 the target value for the calendar year has been 25 micrograms per cubic metre of air (µg/m3). Average annual figures may not exceed that value. In early 2015 the unenforceable target value was converted into a binding limit value.

PM2.5 fine particle values are measured continuously on Friedberger Landstrasse. The target value there was met in 2013 with an annual average of 18.3 µg/m3 (2010: 20.8 µg/m3; 2012: 16.5 µg/m3).

Measures

Reducing emissions

Current clean air measures include expanding the local public transport system, ensuring that the fleet of buses complies with the very latest emission standards and making cycling even more attractive. The plan is for emissions from building heating to be reduced further by expanding the district heating network and enforcing rules on energy-saving construction.